Peel and core the apple. Cut into 12 wedges then chop each wedge into ½” pieces.
Heat a small skillet over medium-high heat. Melt the tablespoon of butter then add the apple pieces, sugar and pinch of cinnamon and salt. Cook until the apples are cooked and browned, about 5 minutes, stirring occasionally. Let cool while you make the muffin batter.
for the muffins
Preheat the oven to 350 degrees F then line a 12-cup muffin pan with paper liners and set aside.
In a large bowl, sift together the flour, baking powder, cinnamon and salt to combine.
In a medium bowl, whisk together the sugar, melted butter, milk, pumpkin puree, vanilla extract and eggs. Stir into the flour mixture until just combined. Scoop the batter evenly into the prepared baking cups.
Bake the muffins for 2 minutes. Quickly and carefully, pull the muffins out of the oven and top each with some of the apple mixture, dividing among the baking cups. Return the muffins to the oven and bake for 20-22 more minutes, or until a toothpick inserted in the center of the muffin comes out clean. Cool the muffins in the pan for 5 minutes then let them cool completely on a wire cooling rack.
for the glaze
Whisk together the confectioners’ sugar, milk and vanilla in a small bowl. If the glaze is too thick, add a little more milk. Drizzle over the cooled muffins and let set for 10 minutes.
Recipe by Lemon & Mocha at http://www.lemonandmocha.com/2018/10/01/apple-pumpkin-muffins/